1. Field of the Invention
The present invention relates to data processing apparatus, such as typewriters or word processors which use a memory to store font or type styles.
2. Description of the Prior Art
Conveniently, a typewriter is known which includes a character generator ROM (referred to as ROM pack hereinafter) which is disconnectable from and connectable with the typewriter proper and which stores dot patterns in accordance with a print font or type style, and a character generator ROM which is incorporated in the typewriter proper and which stores a dot pattern corresponding to a print font or type style (referred to as internal type style hereinafter) different from the first-mentioned type style (referred to as external type style). In the typewriter, there are cases where an external type style is designated and a document stored in a document memory is printed. In those cases, if no external ROM pack which stores the designated type style is connected with the typewriter proper, generally speaking, print in the designated type style is stopped and connection of the ROM pack which stores the designated type style is requested.
There are, however, some cases where print is desired in spite of the particular type style. In addition, there are some cases where print is desired using the internal type style when the ROM pack which stores the designated external type style is not at hand or is lost. In those case, a print type style must be designated again, i.e., this operation is troublesome and the typewriter does not work so efficiently.
Also, there are some circumstances where print is required using a type style which is different from other type styles although the specified details of the difference are not required. Furthermore, there are certain cases where print is desired using a ROM pack at hand which stores an external type style when no ROM pack which stores the designated external type style is at hand. In those cases, however, a print type style must be set again, i.e. this operation is troublesome and the typewriter does not work so efficiently.
In view of the above, it is an object of the present invention to provide a data processing apparatus which performs a print operation using a ROM pack connected to the apparatus although the ROM pack stores an external type style different from that designated when the document is stored, thereby providing enhanced efficiency of print operation.
It is another object of the present invention to provide a data processing apparatus which has a mode of performing a print operation using a character generator ROM which stores an internal type style when a ROM pack which stores an external type style is not connected to the apparatus, thereby providing enhanced efficiency of print operation.